Thus in a manner known for example from the document WO 2007/135383, an aircraft wing element comprising a rigid internal structure portion and a shield which is intended to be exposed to atmosphere during an aircraft flight, can also comprise several components superimposed between this structure portion and this shield. Each of these components is in the form of a layer which is arranged parallel to a surface of the structure portion. These components comprise at least the following three, in the order in which they are listed, starting from the structure portion:                a first temperature sensor, which itself comprises a first support film and at least one first track of a first electrically conductive material with an electrical resistivity value of this first material that varies as a function of its temperature, the first sensor being rigidly connected to the surface of the structure portion;        an electrothermal mat forming a heating element, which is rigidly connected to the first sensor; and        an electrically insulating film, which is rigidly connected to the electrothermal mat by a first face of this insulating film, and connected to the shield by a second face of the same insulating film, and which is capable of transferring heat between these first and second faces of the insulating film.        
When it is supplied with electrical current, the electrothermal mat produces heat, at least part of which diffuses towards the shield with the aim of preventing ice formation or melting any ice which has already accumulated thereon.
The function of the insulating film is to electrically insulate the shield with respect to internal components of the wing element, in particular with respect to the electrothermal mat. It also protects some of these components against electrical discharges which may occur on the shield, in particular lightning strikes.
Finally, the function of the first temperature sensor is to measure the temperature of the electrothermal mat, for example with the aim of regulating this temperature.
However, such wing element does not make it possible to know the temperature of the shield separately from that of the electrothermal mat, or to evaluate the flow of thermal energy that is transferred to the shield when the electrothermal mat is supplied with electrical current.
An object of the present invention is thus to improve such wing element in order to make it possible to measure the temperature of the shield separately from that of the electrothermal mat, and to evaluate the flow of thermal energy that is transferred to the shield.
An additional object is to avoid the modifications introduced by the invention to a wing element causing heat accumulation points between the shield and the electrothermal mat during operation of this latter. In fact, such localized accumulations of heat are likely to degrade the wing element, in particular by affecting or deforming some of its components.